This invention relates to a valve assembly.
The valve assembly of an embodiment of the present invention is particularly adapted to be used within an animal feeding teat. However, other uses of the valve assembly of the present invention are also contemplated.
Traditionally animal feeding teats operate by the feeding animal sucking on the teat to start the flow of liquid. The disadvantage of such teat assembly is that if the opening in the nipple of the teat becomes ripped or broken, the liquid will spill out of the teat even when the animal is not sucking on the teat. Other traditional teats also have the disadvantage that once liquid is flowing through the teat, it will only stop once all the liquid is emptied from the receptacle the teat is attached to. This can cause the animal feeding from the teat to choke on the liquid, or allow spillage and waste of liquid.
Another disadvantage of many traditional feeding teat assemblies is that if the animal pulls the teat to one side, liquid will not flow through the teat. Such teats need to be kept substantially in line with the liquid outlet to operate.
Some teats known in the art contain a valve assembly which operates under the force of gravity to close the valve once it has been opened. The disadvantage of such a teat valve assembly is that it will only operate effectively if the teat is substantially vertical to the ground.
One such invention is described in NZ 110 435. This patent discloses a tubular nozzle that is attached to a container and fitted with an internal rubber covered valve. The free peripheral edge of the nozzle is formed into an upturned flange with curled portion of a flexible teat fitting over and between the flange and the perpendicular wall of the nozzle, with a portion of the teat lying flat against the wall to make an airtight seal. The valve is gravity operated and the teat must be hanging vertically or near vertically for the valve to close.
The invention described in NZ 102 401 is a tubular nozzle fitted to the lower end of a food containing vessel with a resilient teat attached to its end. Inside the nozzle is a valve which consists of a metallic ball-head with a depending stem to the lower end of which is fitted a rubber knob. When an animal sucks the teat, the valve is displaced upwardly and liquid can flow through the teat. When the animal releases the teat, the valve is closed by gravity and no liquid can flow. This construction is also limited to use where the teat hangs vertically or near vertically.
The invention described in NZ 39 125 comprises a containing-vessel for a liquid with a concave or sloping bottom, an angular outlet with a rubber teat at the end thereof for an animal to suck. Within the vessel is a float valve, which may be closed against its seat by the operation of a float or by hand.
In NZ 35 868, there is described a means employed for feeding calves and the like with liquid food. According to this invention, a reservoir for the liquid has a false bottom in which is a valve adapted to close by gravity. A sliding tray beneath the bottom is provided with a float upon one end of a pivoted lever, the other end of which engages a downwardly projecting stem of the valve. The liquid in the tray is thus kept at a predetermined level by the rise and fall of the float. A branch pipe from the tray is connected by a rubber tube or similar flexible connector with a running-pipe supplying the liquid to the animals. Wastage is prevented by locating the orifices from the pipe to the teats on a level with, or slightly higher than, the surface of the liquid in the tray.
The invention in U.S. Pat. No. 5,638,769 discloses a teat comprising a hollow body made of a resilient material. The body has an inlet and an outlet end. The outlet end includes at least one slit through the wall of the body. This slit(s) does not extend into that area of the wall of the body which forms the extremity of the outer end. Engaged with the inlet end is a valve biased by a spring. As an animal suckles on the teat a pressure differential forms within. This suction causes the valve to open allowing liquid to fill the teat. When the suction is removed the valve closes. The closed valve prevents any backflow when the teat is squeezed.
GB 2 267 549 discloses a teat valve comprising an apertured closure member which co-operates with a tubular seat and an elastic sleeve which houses both the member and the seat and urges them into sealing engagement. When the sleeve is stretched, the valve opens allowing passage of liquids/solubles and gases, and when released returns to its original position, thus closing the valve.
It is an object of the present invention to provide a valve assembly adapted for use in an animal feeding teat which will go some way towards overcoming the above-mentioned disadvantages or which will at least provide the public with a useful choice.
This invention can be said broadly to consist in a valve assembly adapted for use in an animal feeding teat, said valve assembly comprising
a piston shaft with a piston head,
a valve head attached to the piston shaft at the end of the shaft opposite the piston head, and
biasing means co-operable with said piston head,
so that in use in an animal feeding teat said valve head is seated to cover a first aperture in said teat and pressure applied by said animal on said teat causes said teat to act directly on said piston head to move said valve assembly against said biasing means to unseat said valve head and open said aperture.
Preferably the piston head is bulbous in shape.
Preferably the piston head is tapered at the end remote from the valve head.
Preferably the biasing means is a spring.
Preferably the spring is a coil spring.
Most preferably the spring is comprised of stainless steel.
Preferably the spring is coiled around the piston shaft.
Preferably the piston head contains at least one recess.
Preferably the piston shaft, piston head and valve head are formed as one unit. Preferably that unit is comprised of nylon.
The invention can also be said broadly to consist in a combination of an animal feeding teat with the valve assembly described above.
Preferably the teat comprises:
an outer casing,
a first aperture at one end of the casing connectable to a source of fluid, through which the valve head of the valve assembly protrudes, and
at least one second aperture in the outer casing through which liquid can flow to feed the animal,
whereby when pressure is applied onto the piston head, the valve head is unseated from the first aperture to allow fluid to flow through the first aperture into the outer casing and subsequently out of the second aperture and closes when the pressure is removed from said piston head.
In one alternative the pressure is applied by an animal""s mouth or teeth through said outer casing. In another alternative the pressure is applied by the atmosphere on the outer casing when an animal sucks on the teat thereby creating a partial vacuum within the teat.
Preferably the second aperture is located at the opposite end of the casing from the end where the valve head protrudes.
Preferably the teat is comprised of either a durable pliant synthetic material or rubber. The rubber may be natural or synthetic.
The invention may further be said to broadly consist in an animal feeding teat adapted to allow incorporation of the valve assembly described above.
The invention may also be said broadly to consist in a valve assembly substantially as herein described with reference to the accompanying drawings.
The invention may also be said to broadly consist in an animal feeding teat substantially as herein described with reference to the accompanying drawings.
The invention may also be said broadly to consist in a combination substantially as herein described with reference to the accompanying drawings.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
This invention consists in the foregoing and also envisages constructions of which the following gives examples.